A new study from New York City College of Technology sheds light on how a deflection strategy would work best in order to avoid collision with giant space objects such as asteroids.
“A collision with an object of this size travelling at an estimated 30,000 to 40,000 mile per hour would be catastrophic,” said NASA researcher and New York City College of Technology (City Tech) Associate Professor of Physics Gregory L. Matloff.
His advice is to “either destroy the object or alter its trajectory.” In 2029 and 2036, the asteroid Apophis (named after the Egyptian god of darkness and the void), at least 1,100 feet in diameter, 90 stories tall, and weighing an estimated 25 million tons, will make two close passes by Earth at a distance of about 22,600 miles.
According to the researcher, diverting objects such as these is a better option than exploding them as the debris itself could bathe Earth in a radioactive shower.
His study indicates that an asteroid could be diverted by heating its surface to create a jet stream, which would alter its trajectory, causing it to veer off course.
And to do that, one needs to know how deeply the light would need to penetrate the NEO’s (near Earth object) surface.
“A beam that penetrates too deeply would simply heat an asteroid but a beam that penetrates just the right amount - perhaps about a tenth of a millimetre - would create a steerable jet and achieve the purpose of deflecting the asteroid,” said Matloff.
Matloff and his colleagues have been experimenting with red and green lasers to see how deeply they penetrate asteroidal rock, using solid and powdered (regolith) samples from the Allende meteorite that fell in Chihuahua, Mexico in 1969.